1. Black magnetic iron oxide particles which comprise core particles and a surface layer formed on the respective core particles and which have an average particle diameter of 0.05 to 2.0 \u03bcm and an electric resistance value RM100 at an applied voltage of 100 V of not less than 1\xd7108 \u03a9\xb7cm.
2. Black magnetic iron oxide particles according to claim 1, wherein the black magnetic iron oxide particles comprise core particles and a surface layer formed on the respective core particles the surface layer comprises one or more elements selected from the group consisting of Al, Mg, Mn, Zn, Ni, Cu, Ti and Si, and the elements are present in an amount of 0.3 to 4.5% by weight in the surface layer.
3. Black magnetic iron oxide particles according to claim 1, wherein the black magnetic iron oxide particles have a water absorption Ma0.9 of not more than 15 mgg.
4. Black magnetic iron oxide particles according to claim 1, wherein the black magnetic iron oxide particles have an electric resistance value RM10 at an applied voltage of 10 V which satisfies the relationship represented by the formula:
0.5\u2266RM100RM10\u22661.
5. A magnetic carrier for electrophotographic developer comprising spherical magnetic composite particles obtained by dispersing black magnetic iron oxide particles as defined in claim 1 in a binder resin, wherein the magnetic carrier has an electric resistance value R100 at an applied voltage of 100 V of 1\xd7108 to 1\xd71014 \u03a9\xb7cm, and an electric resistance value R300 at an applied voltage of 300 V which satisfies the relationship represented by the formula:
0.1\u2266R300R100\u22661,
wherein the total content of the magnetic iron oxide particles in the spherical magnetic composite particles is 80 to 99% by weight based on the weight of the spherical magnetic composite particles.
6. A magnetic carrier for electrophotographic developer according to claim 5, wherein the binder resin is a phenol resin.
7. A magnetic carrier for electrophotographic developer according to claim 5, wherein a surface coating layer mainly comprising a resin is formed on a surface of the respective spherical magnetic composite particles.
8. A two-component electrophotographic developer comprising the magnetic carrier for electrophotographic developer as defined in claim 5.
9. A magnetic carrier for electrophotographic developer according to claim 5, having a saturation magnetization value of 40 to 100 Am2kg when applying an external magnetic field of 795.8 kAm (10 kOe).
10. A magnetic carrier for electrophotographic developer according to claim 5, having a saturation magnetization value of 71.3 to 100 Am2kg when applying an external magnetic field of 795.8 kAm (10 kOe).
11. A magnetic carrier for electrophotographic developer according to claim 5, wherein a total content of the magnetic iron oxide particles in the spherical magnetic composite particles is 85 to 99% by weight based on the weight of the spherical magnetic composite particles.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A disk drive assembly for mounting in an enclosure, the enclosure having a bar arranged therein, the disk drive assembly comprising:
a disk drive having a top surface, opposite side surfaces and a back surface perpendicular to the top surface, the disk drive having a first output connecter provided on the back surface;
a mounting bracket having a pair of side flanges and a mounting board attached to the back surface of the disk drive, a guiding rail formed on each side flange, a foot extending from each of the guiding rails to attach to a corresponding one of the side surfaces of the disk drive, and a resilient arm with a protrusion formed thereon for engaging with the bar; and
a converter card received between the guiding rails of the mounting bracket, the converter card having a circuit board parallel to the top surface of the disk drive, an input connecter formed on the circuit board and connected to the first output connecter, and a second output connecter formed on the circuit board for connecting to a data signal cable, wherein the mounting bracket with the converter card is absolutely positioned at a back side of the disk drive adjacent to the back surface of the disk drive.
2. The disk drive assembly as described in claim 1, wherein the resilient arm has a flat portion with the protrusion formed thereon, the protrusion has a first side surface substantially perpendicular to the flat portion and a second side surface slopes down in a direction away from the disk drive; the first side surface faces toward the disk drive for engagement with the bar.
3. The disk drive assembly as described in claim 1, wherein the mounting bracket has a flat body parallel to the top surface of the disk drive for mounting the converter card thereto.
4. The disk drive assembly as described in claim 1, wherein a thickness of the mounting bracket is not larger than a thickness of the disk drive.
5. An electronic device comprising:
an enclosure having a bar;
a disk drive mounted in the enclosure, the disk drive having a top surface, a back surface perpendicular to the top surface, and a first output connecter on the back surface;
a mounting bracket attached to the disk drive adjacent to the back surface thereof, the mounting bracket comprising a flat body, and a resilient arm attached to the body, the resilient arm being engaged with the bar such that the disk drive is blocked from moving toward the bar in the enclosure, the resilient arm being manually bendable so as to disengage from the bar, a height of the mounting bracket is not greater than a thickness of the disk drive; and
a converter card having an input connecter connected to the first output connecter, and a second output connecter for connecting to a motherboard in the enclosure.
6. The electronic device assembly as described in claim 5, wherein the resilient arm has a flat portion with the protrusion formed thereon, a protrusion is formed on the resilient arm, the protrusion has a first side surface substantially perpendicular to the flat portion and a second side surface slopes down in a direction away from the disk drive; the first side surface faces toward the disk drive for engagement with the bar.
7. The electronic device assembly as described in claim 5, wherein the mounting bracket has a pair of side flanges formed on opposite edges of the flat body, and each side flange has a guiding rail for receiving the converter card therein.
8. The electronic device assembly as described in claim 5, wherein the mounting bracket has a pair of feet attached to opposite sides of the disk drive.